PF-ChiA is an uncharacterized chitinase found in the hyperthermophilic archaeon Pyrococcus furiosus with a glycosyl hydrolase family 18 (GH18) catalytic domain as well as a cellulose-binding domain. Members of this domain family are found not only in archaea but also in eukaryotes and prokaryotes. PF-ChiA exhibits hydrolytic activity toward both colloidal and crystalline (beta/alpha) chitins at high temperature.

Domain of unknown function (DUF5011). This small family of proteins is functionally uncharacterized. This family is found in Bacteroides, Prevotella, and Parabateroides. Proteins in this family are around 230 amino acids in length.

chitin-binding domain of Chi A1-like proteins. This group contains proteins related to the chitin binding domain of chitinase A1 (ChiA1) of Bacillus circulans WL-12. Glycosidase ChiA1 hydrolyzes chitin and is comprised of several domains: the C-terminal chitin binding domain, an N-terminal and catalytic domain, and 2 fibronectin type III-like domains. Chitinases function in invertebrates in the degradation of old exoskeletons, in fungi to utilize chitin in cell walls, and in bacteria which use chitin as an energy source. Bacillus circulans WL-12 ChiA1 facilitates invasion of fungal cell walls. The ChiAi chitin binding domain is required for the specific recognition of insoluble chitin. although topologically and structurally related, ChiA1 lacks the characteristic aromatic residues of Erwinia chrysanthemi endoglucanase Z (CBD(EGZ)).

Cellulose binding domain. Two tryptophan residues are involved in cellulose binding. Cellulose binding domain found in bacteria.

CBD_II domain.

Crystalstructure of catalytic domain of hyperthermophilic chitinase from Pyrococcus furiosus [Pyrococcus furiosus],2DSK_B Crystal structure of catalytic domain of hyperthermophilic chitinase from Pyrococcus furiosus [Pyrococcus furiosus]

Crystalstructures of catalytic site mutants of active domain 2 of thermostable chitinase from Pyrococcus furiosus complexed with chito-oligosaccharides [Pyrococcus furiosus],3A4W_B Crystal structures of catalytic site mutants of active domain 2 of thermostable chitinase from Pyrococcus furiosus complexed with chito-oligosaccharides [Pyrococcus furiosus]

Crystalstructures of catalytic site mutants of active domain 2 of thermostable chitinase from Pyrococcus furiosus complexed with chito-oligosaccharides [Pyrococcus furiosus],3A4X_B Crystal structures of catalytic site mutants of active domain 2 of thermostable chitinase from Pyrococcus furiosus complexed with chito-oligosaccharides [Pyrococcus furiosus],3AFB_A Crystal structures of catalytic site mutants of active domain 2 of chitinase from Pyrococcus furiosus [Pyrococcus furiosus],3AFB_B Crystal structures of catalytic site mutants of active domain 2 of chitinase from Pyrococcus furiosus [Pyrococcus furiosus]

SolutionNMR structure of a Bacterial Ig-like (Big_3) domain from Bacillus cereus. Northeast Structural Genomics Consortium target BcR147A [Bacillus cereus ATCC 14579]

ChainA, CHITINASE A1 [Niallia circulans]

Probable bifunctional chitinase/lysozyme OS=Escherichia coli (strain K12) OX=83333 GN=chiA PE=1 SV=2

Endochitinase 11 OS=Metarhizium anisopliae OX=5530 GN=chi11 PE=1 SV=1

Chitinase OS=Saccharopolyspora erythraea (strain ATCC 11635 / DSM 40517 / JCM 4748 / NBRC 13426 / NCIMB 8594 / NRRL 2338) OX=405948 GN=chiA2 PE=1 SV=2

Chitinase D OS=Niallia circulans OX=1397 GN=chiD PE=1 SV=4

Chitinase A1 OS=Niallia circulans OX=1397 GN=chiA1 PE=1 SV=1